pandas.Series.duplicated

Series.duplicated(self, keep=‘first‘)

Indicate duplicate Series values.

Duplicated values are indicated as True values in the resulting Series. Either all duplicates, all except the first or all except the last occurrence of duplicates can be indicated.

Examples：

By default, for each set of duplicated values, the first occurrence is set on False and all others on True:

>>> animals = pd.Series([‘lama‘, ‘cow‘, ‘lama‘, ‘beetle‘, ‘lama‘])
>>> animals.duplicated()
0    False
1    False
2     True
3    False
4     True
dtype: bool

which is equivalent to

>>> animals.duplicated(keep=‘first‘)
0    False
1    False
2     True
3    False
4     True
dtype: bool

>>> animals.duplicated(keep=‘last‘)
0     True
1    False
2     True
3    False
4    False
dtype: bool

>>> animals.duplicated(keep=False)
0     True
1    False
2     True
3    False
4     True
dtype: bool

pandas.Series.duplicated

原文：https://www.cnblogs.com/zjuhaohaoxuexi/p/11914671.html